Grammar Rule in 30 Seconds
Use 'but' to join two ideas in one sentence, and 'however' to start a new, more formal sentence.
- Use 'but' with a comma to connect two clauses: 'I'm tired, but I'm working.'
- Use 'however' at the start of a new sentence followed by a comma.
- Never use 'however' as a simple replacement for 'but' between two commas.
Overview
but と however です。but と however の違いは、単なる「言葉の響き」の差ではありません。これらは文法上の役割（品詞）が根本的に異なり、それに伴って「句読点（Punctuation）の打ち方」や「文の中での位置」が厳格に決まっています。but と however の最大の違いは、それらが「文法的にどのような力を持っているか」という点にあります。これらを日本語の感覚で捉えるのではなく、英語特有の「文の構造」の観点から見ていきましょう。but：二つの要素を「接着」するbut は Coordinating Conjunction（等位接続詞） と呼ばれるグループに属します。等位接続詞とは、二つの対等な要素（単語と単語、句と句、あるいは節と節）を強力な接着剤のように繋ぐ役割を果たします。- 特徴: 二つの独立した文（節）を一つの文にまとめ上げます。
- 日本語との比較: 日本語の「A。でもB。」という二つの文を、「A、しかしB」という一つの文に繋ぐ感覚に近いです。ただし、英語の
butは文と文を繋ぐ際、通常はその前にカンマ,を必要とします。
I studied hard, but I failed the exam.（一生懸命勉強したが、試験に落ちた。）I studied hard と I failed the exam という二つの独立した考えが、but という接着剤によって一つの「複文」になっています。however：二つのアイデアの間に「橋を架ける」however は Conjunctive Adverb（接続副詞） です。名前に「副詞」とある通り、これは本来、文を繋ぐ接着剤としての機能は持っていません。前の文の内容を受けて、「それとは対照的に」という「意味」を添えるだけの役割です。- 特徴: 二つの独立した文を文法的に繋ぐことはできません。あくまで「前の文」と「今の文」の論理的な関係性を示す「橋」のような存在です。
- 日本語との比較: 日本語の「しかしながら」や「一方で」に相当します。非常にフォーマルな響きを持ち、書き言葉やプレゼンテーションで好まれます。
I studied hard. However, I failed the exam.（一生懸命勉強した。しかしながら、試験に落ちた。）. で一度文が切れています。however は新しい文の冒頭で、前の文との対比を示しているに過ぎません。butのニュアンス: 比較的カジュアルから標準的な表現で、日常会話や気軽なメールで多用されます。対比の度合いは「自然な逆転」や「予想される範囲内の例外」を指すことが多いです。howeverのニュアンス: 非常にフォーマルで、論理的な重みがあります。また、butよりも「驚き」や「強い対照」を強調する効果があります。ビジネスの商談や学術論文、就職活動（就活）のカバーレターなどで必須となる表現です。
but の基本パターンbut は常に二つの要素の「間」に置かれます。文頭に置くことは、現代の口語では許容されますが、アカデミックなライティングや正式なビジネス文書では避けるのが一般的です。but 文B. | The hotel was expensive, but the service was poor. | 二つの独立した節を繋ぐ場合、but の前にカンマを置くのが標準的です。 |but 形容詞B | The movie was long but interesting. | 単語同士を繋ぐ場合は、カンマは不要です。 |however の基本パターンhowever の最大の特徴は、文の中での「位置の自由度」です。これが but との決定的な構造的違いです。However, で始めます。必ず直後にカンマを打ちます。The sales target was high. However, we achieved it ahead of schedule.
however を使いたい場合はセミコロン ; を使います。The sales target was high; however, we achieved it ahead of schedule.
however を挟み込みます。この場合、however を二つのカンマで囲みます。The sales target was high. We, however, achieved it ahead of schedule.
We）を強調したい時に非常に有効です。The sales target was high. We achieved it ahead of schedule, however.
but が圧倒的に自然です。友達との会話で however を連発すると、日本語で「しかしながら、私は昨日...」と話し始めるような、非常に堅苦しく、少し不自然な印象を与えてしまいます。I wanted to go to the party, but I had to work.(パーティーに行きたかったんだけど、仕事があったんだ。)
however を積極的に使いましょう。特に、悪いニュースを伝える際（クッション言葉として）や、複雑な状況を説明する際に役立ちます。We appreciate your proposal. However, we have decided to go with another vendor.(ご提案には感謝いたします。しかしながら、今回は別の業者と契約することにいたしました。)
However, が非常に効果的です。一拍置くことで、聴衆の注意を引くことができます。but: 「AだけどB」という、並列に近い逆接。however: 「Aである。それにもかかわらず（驚くべきことに）Bである」という、より強い対比。
however を繋いでしまう人が後を絶ちません。- NG:
It was raining, however we went out. - OK:
It was raining; however, we went out.またはIt was raining. However, we went out.
however にも同じ「接続」の力を期待してしまうからです。英語の however はあくまで「副詞」であることを忘れないでください。But の乱用But, ... という形になって現れます。- NG (in formal writing):
But, the results were different. - OK:
However, the results were different.
but は本来、何かと何かを繋ぐためのものなので、文頭に置くと「何と繋がっているのか？」が文法的に不明確になります。カジュアルな会話なら問題ありませんが、B1レベル以上のライティングでは However を使うのが正解です。but の後のカンマHowever, の後には必ずカンマを打ちますが、but の後には通常カンマは打ちません。これを混同するケースが目立ちます。- NG:
I like apples, but, I don't like oranges. - OK:
I like apples, but I don't like oranges.
but と however 以外にも、逆接や譲歩を表す表現はたくさんあります。これらを整理して、表現の幅を広げましょう。but | 等位接続詞 | 最も一般的。文中で二つの節を繋ぐ。 | Simple, but effective. |however | 接続副詞 | フォーマル。文頭・文中・文末で使える。 | However, there is a catch. |although | 従属接続詞 | 「〜だけれども」。文全体に「譲歩」の意味を加える。 | Although it was cold, we swam. |though | 従属接続詞 | although よりカジュアル。文末に置くことも多い。 | It was hard work, though. |yet | 等位接続詞 | but よりも「意外性」が強い。少し古風・文学的。 | Strange, yet true. |nevertheless | 接続副詞 | however よりもさらにフォーマル。「それにもかかわらず」。 | The task was difficult; nevertheless, he finished it. |although との使い分けに注意してください。although は「AだけれどもB」という一つのパッケージを作る接続詞です。一方で but は「A、でもB」という対等な関係です。これらを一つの文で同時に使う（Although A, but B.）のは二重表現となり、英語では明確な間違いになります。But を使うのは絶対にダメですか？But が使われることはよくあります。ただし、TOEFLやIELTSなどの試験、あるいはビジネス上の正式なレポートでは、However を使うか、文を繋げて but を使う方が「教育を受けた人の英語」として評価されます。however を文の中に挟む（パターンC）メリットは何ですか？The price, however, is too high. と言うと、単に「しかし価格が高い」と言うよりも、「価格」という要素にスポットライトが当たり、聞き手に強い印象を残すことができます。プレゼンなどで特定の懸念事項を強調したい時に非常に有効なテクニックです。but の前にカンマを忘れたら間違いですか？I'm tired but happy.）であれば省略されることもありますが、B1レベルの学習者としては「文と文を繋ぐ but の前にはカンマを置く」と覚えておくのが最も安全で、間違いのない書き方です。but です。日本語の「しかしながら」や「ですが」に近いのが however だと考えると、フォーマル度の違いがイメージしやすいでしょう。就活の面接やビジネスの会議では however 的な意識を持ち、飲み会やランチの席では but 的な意識で話すと、状況に合った自然な英語になります。Punctuation Patterns for Contrast
| Connector | Position | Preceding Punctuation | Following Punctuation |
|---|---|---|---|
|
but
|
Middle of sentence
|
Comma (,)
|
None
|
|
however
|
Start of sentence
|
Period (.)
|
Comma (,)
|
|
however
|
Middle (joining clauses)
|
Semicolon (;)
|
Comma (,)
|
|
however
|
Middle (parenthetical)
|
Comma (,)
|
Comma (,)
|
|
but
|
Start of sentence (informal)
|
None
|
None
|
Meanings
Both words are used to introduce a statement that contrasts with or contradicts what has just been said.
Direct Contrast
Showing a simple difference between two facts.
“He is tall, but his brother is short.”
“The car is old. However, it is very reliable.”
Concession
Acknowledging a fact before introducing a surprising contrast.
“It was expensive, but worth it.”
“The plan was risky. However, they decided to proceed anyway.”
Interruption/Correction
Using the word to stop a flow of thought and pivot.
“But wait, there's more!”
“The results were positive. However, we must consider the margin of error.”
Reference Table
| 特徴 | But | However |
|---|---|---|
|
文法上の役割
|
Coordinating Conjunction (等位接続詞)
|
Conjunctive Adverb (接続副詞)
|
|
句読点
|
節をつなぐ前にカンマを置く
|
前にセミコロンかピリオド、後ろにカンマ
|
|
トーン
|
カジュアル、日常会話、直接的
|
フォーマル、構造的、強い対比
|
|
つなぐ対象
|
1つの文の中にある2つの節
|
2つの独立した文や節
|
|
主な用途
|
シンプルな対比や例外
|
大きな方針転換や複雑なアイデア
|
|
文頭での使用
|
カジュアルならOK（フォーマルでは避ける）
|
非常に一般的（常にカンマを伴う）
|
フォーマル度スペクトル
I would like to assist you; however, I am currently unavailable. (Offering assistance)
I want to help, but I'm busy right now. (Offering assistance)
I'd help, but I can't. (Offering assistance)
Wish I could help, but nah. (Offering assistance)
But vs. However: 概念マップ
But
- 等位接続詞 Connects two independent clauses.
- カジュアル/日常的 Used in everyday speech and writing.
- カンマの句読点 Typically preceded by a comma.
However
- 接続副詞 Connects two sentences or independent clauses.
- フォーマル/構造的 Used in more formal or academic contexts.
- セミコロン/ピリオド Requires specific punctuation like a semicolon before or period before, with a comma after.
But vs. However: クイック比較
But か However かの選択フローチャート
対照的な2つの考えをつなげますか？
両方の部分は独立した文として成立しますか？
カジュアルで直接的なトーンにしたいですか？
フォーマルなトーンや、2つの考えの強い区切りが必要ですか？
文脈がカギ！
BUT を使う場面:
- • 友達へのチャット
- • 日常会話
- • Netflixの字幕
- • 素早い反論
HOWEVER を使う場面:
- • 採用面接
- • フォーマルなメール
- • 学術論文
- • プレゼンテーション
レベル別の例文
I am tall, but my sister is short.
I am tall, but my sister is short.
It is sunny, but it is cold.
It is sunny, but it is cold.
I like tea, but I hate coffee.
I like tea, but I hate coffee.
She is tired, but she is happy.
She is tired, but she is happy.
The food was good, but the service was slow.
The food was good, but the service was slow.
I want to go. However, I have no money.
I want to go. However, I have no money.
He studied hard, but he failed the test.
He studied hard, but he failed the test.
It was a long trip. However, it was fun.
It was a long trip. However, it was fun.
We arrived on time, but the meeting had already started.
We arrived on time, but the meeting had already started.
The company is growing. However, profits are still low.
The company is growing. However, profits are still low.
I've seen that movie, but I don't remember the ending.
I've seen that movie, but I don't remember the ending.
The app is free; however, you must pay for extra features.
The app is free; however, you must pay for extra features.
The research is promising, but further testing is required.
The research is promising, but further testing is required.
The government promised reform. However, little has changed so far.
The government promised reform. However, little has changed so far.
She was exhausted; however, she refused to stop running.
She was exhausted; however, she refused to stop running.
The design is beautiful. It is, however, very difficult to build.
The design is beautiful. It is, however, very difficult to build.
The policy is effective in theory, but its practical application remains problematic.
The policy is effective in theory, but its practical application remains problematic.
The economy is recovering. However, the unemployment rate remains stubbornly high.
The economy is recovering. However, the unemployment rate remains stubbornly high.
He was a brilliant scientist, but his social skills were notoriously lacking.
He was a brilliant scientist, but his social skills were notoriously lacking.
The evidence is compelling; however, it does not constitute absolute proof.
The evidence is compelling; however, it does not constitute absolute proof.
The prose is elegant, but the narrative arc feels somewhat contrived.
The prose is elegant, but the narrative arc feels somewhat contrived.
The treaty was signed in haste. However, the long-term implications were not fully considered.
The treaty was signed in haste. However, the long-term implications were not fully considered.
The system is robust; however, it is not entirely immune to sophisticated cyber-attacks.
The system is robust; however, it is not entirely immune to sophisticated cyber-attacks.
The protagonist is flawed, but her resilience makes her deeply sympathetic.
The protagonist is flawed, but her resilience makes her deeply sympathetic.
間違えやすい
Learners try to use both in the same sentence.
They mean the same thing, but 'nevertheless' is much more formal.
Both are FANBOYS, but 'yet' implies a sense of surprise.
よくある間違い
I like cat but I like dog.
I like cats, but I like dogs.
But I am hungry.
I am hungry.
I am tall but, he is short.
I am tall, but he is short.
He is rich but he is sad.
He is rich, but he is sad.
I like coffee, however I hate tea.
I like coffee. However, I hate tea.
The car is old however it works.
The car is old; however, it works.
I am tired however, I will go.
I am tired. However, I will go.
We wanted to go, however, it rained.
We wanted to go; however, it rained.
The plan was good but, it was too expensive.
The plan was good, but it was too expensive.
However I tried, I failed.
However hard I tried, I failed.
The results were significant, however, they were not conclusive.
The results were significant; however, they were not conclusive.
But, the evidence suggests otherwise.
However, the evidence suggests otherwise.
He was however, a good man.
He was, however, a good man.
文型パターン
I like ___, but I don't like ___.
The weather was ___. However, we decided to ___.
___ is a great city; however, it is very ___.
The project, however, was ___ by the ___.
Real World Usage
I'm coming but I'll be late!
I haven't worked in retail. However, I have great people skills.
The data is limited; however, the trend is clear.
Love the new update but the UI is weird.
I'd like the burger, but without onions please.
We received your request. However, we need more information.
句読点に注意して！
however の句読点です。前にセミコロンかピリオド、後ろにカンマを置くのが鉄則ですよ。 "I'm tired; however, I'll work."流れを大事にするなら 'But'
but が最適です。会話が止まらず流れる感じになります。 "I'm hungry, but I'll wait."迷ったら文を分けよう！
However, で始めてみてください。これだけでミスが減りますよ！ "It's hard. However, it's fun."フォーマル vs カジュアル
But で始めるより However, を使う方が洗練された印象を与えられます。 However, we disagree.声に出して読んでみて
but、少し間を置いて強調したいなら however がぴったりです。リズムを感じてみましょう。 "I like it, but it's old."表現の幅を広げよう
yet や although なども混ぜると、英語がもっとダイナミックで面白くなりますよ！ He is small, yet strong.
Smart Tips
It is almost certainly 'However'.
Replace 'but' with 'however' to sound more polite and competent.
Put 'however' between two commas right after the subject.
Stick to 'but'. Using 'however' too much in a bar or with friends can sound a bit stiff.
発音
But Stress
In normal speech, 'but' is usually unstressed and sounds like /bət/.
However Pause
There is always a slight pause after 'however' when it starts a sentence, indicated by the comma.
Contrastive Rise
I like it, ↗ but... ↘
The voice rises on the first clause and falls after 'but'.
暗記しよう
記憶術
BUT is a Bridge (connects one sentence). HOWEVER is a Highway (moves you between two sentences).
視覚的連想
Imagine 'but' as a small piece of tape holding two papers together. Imagine 'however' as a large signpost standing between two separate buildings.
Rhyme
Use 'but' to stay in the same place, use 'however' to start a new space.
Story
A traveler reached a river. He wanted to cross, BUT he had no boat. He looked around for hours. HOWEVER, he eventually found a bridge further downstream.
Word Web
チャレンジ
Write three sentences about your favorite food. Use 'but' in the first, 'however' at the start of the second, and 'however' with a semicolon in the third.
文化メモ
British speakers often use 'mind you' as an informal alternative to 'however' at the end of a sentence.
In US and UK universities, starting a sentence with 'But' is often discouraged by professors to promote a more formal 'However'.
Using 'however' in emails is seen as a way to soften bad news or a disagreement.
'But' comes from Old English 'be-utan', meaning 'outside'. 'However' is a combination of 'how' and 'ever', appearing in Middle English.
会話のきっかけ
Do you prefer city life or country life? (Use 'but')
What is a movie you liked? (Use 'however')
Discuss the pros and cons of social media.
Argue for or against remote work.
日記のテーマ
よくある間違い
Test Yourself
The concert was sold out, ___ we still managed to get tickets from a friend.
Find and fix the mistake:
The restaurant was fully booked, however we found a table at a cafe nearby.
正しい文を選んでください：
「映画に行きたかったのですが、仕事をしなくてはいけませんでした。」
Answer starts with: ["I...
Score: /4
練習問題
8 exercisesI love swimming, ___ I don't like the ocean.
The exam was difficult. ___, I passed.
Find and fix the mistake:
I am tired, however I will finish.
It was raining, but we went to the park.
1. But, 2. However, 3. Nevertheless
A: Did you like the hotel? B: It was clean. ___, it was too noisy.
Choose the correct one:
Score: /8
Practice Bank
12 exercisesI love playing video games, ___ I'm terrible at them.
The forecast predicted rain; but, the sun came out.
正しい文はどれですか？
「あなたを助けたいのですが。しかし、今は自由な時間がありません。」
単語を並べ替えて文を作ってください：
用語を組み合わせてください：
The new policy faced some opposition; ___, it was ultimately approved.
We planned a picnic, however the weather turned bad.
正しい文を選んでください：
「コーヒーは熱かったけれど、すぐに飲みました。」
並べ替えて文を完成させてください：
文を完成させてください：
Score: /12
よくある質問 (8)
Yes, you can, especially in informal writing or speech. However, in very formal academic essays, it is better to use `However` or `Nevertheless`.
The comma signals a pause, showing that `however` is a transition word (conjunctive adverb) and not part of the subject or verb.
Yes, significantly. `But` is neutral and common in speech, while `however` is the standard for professional and academic writing.
Usually, no. It would be redundant. Choose the one that fits your punctuation and register.
A comma splice is when you join two full sentences with only a comma. Using `however` with just a comma (e.g., 'I'm tired, however I'm going') is a classic comma splice.
Yes! For example: 'The food was expensive. It was delicious, however.' This is common in spoken English.
If it is joining two independent clauses (full sentences), yes. If it is just joining two words (e.g., 'small but strong'), no comma is needed.
They are very similar, but `nevertheless` is even more formal and emphasizes that something happened *despite* the previous point.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
pero / sin embargo
Punctuation rules for 'pero' are slightly more relaxed than for 'but'.
mais / pourtant
French 'mais' can be used at the start of a sentence more formally than 'but'.
aber / jedoch
German 'jedoch' can move around the sentence much like 'however'.
demo / shikashi
Japanese doesn't use a comma before 'demo' in the same way English uses one before 'but'.
lakin / ma'a dhalika
Arabic sentences are often much longer, using 'but' to connect multiple ideas.
danshi / ran'er
The 'Although... but...' double connector is the biggest hurdle for Chinese learners.
Learning Path
Prerequisites
関連動画
Related Grammar Rules
方言 vs. 言語：違いは何ですか？
### Overview 言語（language）と方言（dialect）の区別は、言語学において最も有名で、かつ最も難しい問題の一つです。「言語...
Nowadays vs. Now-a-days: 違いは何ですか？
### Overview 英語を学習していると、似たような意味を持つ単語や、スペリングが紛らわしい表現に遭遇することが多々あります。...
Let them vs. Let they: 違いは何ですか？
### Overview 英語を学習する際、多くの日本人が最初に直面する壁の一つが「代名詞の格（Case）」の変化です。日本語では「彼」...
Quite vs. Quiet: 違いは何ですか？
### 概要 (Overview) 英語を学習する上で、多くの日本人学習者が頭を悩ませるのが「スペルが似ているけれど意味が全く異なる単...
Said vs. Told: 違いは何ですか？
### Overview 英語を学習している皆さんにとって、`say` と `tell` の使い分けは、中級レベル（B1）に到達する際に必ずと言って...
